Dallas-based AT&T Inc. said Monday that it has a multiyear agreement with OnStar to provide advanced wireless service to millions of General Motors vehicles beginning with the 2015 model year.

Verizon Wireless previously had the contract with OnStar, a GM subsidary, and will continue to provide service to existing vehicles.

Cellphone companies are jostling to connect nonphone devices to their networks. Now that nearly everyone has a cellphone, the companies have to look elsewhere for growth. AT&T has been particularly aggressive, garnering, for instance, the contract to connect Amazon Kindle e-readers.

AT&T said it will provide 4G LTE mobile Internet access for GM’s safety and security services offered by OnStar, as well as information and entertainment services, such as video for back-seat passengers.

“Through this built-in 4G LTE connection we have the opportunity to reinvent the mobile experience inside a vehicle,” Mary Chan, president, Global Connected Consumer, General Motors, said in a statement.

For example, GM could deliver car software updates wirelessly, instead of making owners take their cars to the shop. It could also enable video streaming for passengers, provide in-vehicle Wi-Fi hot spots and give GM a better view of what’s going on inside a car and determine whether it needs maintenance. Owners might even be able to call up views from their car’s cameras, remotely.